WARSAW -- In an unusual and as-yet-unexplained management bloodletting, the supervisory board of Polkomtel SA, Poland's second-ranked mobile-phone operator, has sacked four of its top six executives, including its chief executive.

The company's main shareholders, which include TeleDanmark AS and Vodafone Group PLC, each with a 19.6% stake, hadn't agreed on a replacement for Chief Executive Wladyslaw Bartoszewicz.